下图描述的是一定时期内某地猪肉的需求曲线由D₁左移到D₂。下列事件中能导致这种变动关系的是

①养猪业社会劳动生产率普遍提高 

②市场上其他肉类供应量大幅增加 

③该地区居民的收入水平大幅提高 

④媒体曝光40吨病死猪肉销往该地

A．②③

B．①④

C．①③

D．②④

Passage 1: The Blacks had never been rich enough to spend their summer holidays in a luxurious place. This year, however, Mr. Black made a lot of money and his wife said that she would like to go to Rome for a change. Mr. Black thought it’s a good idea. He said they should stay at a really good hotel while they went around the famous city.They flew to Rome, and arrived at their hotel late one evening. They thought that they would have to go to bed hungrily because no meals were served in cheap hotels where they used to stay. They were therefore surprised when the waiter asked whether they would be having dinner there at night.“Are you still serving dinner now” asked Mrs. Black. “Certainly, madam.” answered the waiter. “We serve it until half past nine.”“What are the time for meals then” asked Mrs. Black.“We serve breakfast from seven to half past eleven in the morning, lunch from twelve to three, tea from four to five and dinner from six to half past nine.”“But that hardly leaves any time for us to see the sights of Rome!” said Mrs. Black in a disappointed voice.

On the first evening in Rome they thought ________.

A．they would go to bed without having dinner

B．meals were served at that time in the hotel

C．they wouldn’t take dinner until half past nine

D．dinner was not necessary